A technique of producing a contour map of the optic nerve head by computer processing of stereophotographs of the fundus has been developed at Stanford Research Institute. It is proposed to test the reproducibility and sensitivity of this system on normal human subjects and to improve the computer processing to optimize the results. Patients with elevated intraocular pressure will be followed in order to find if the method is a more delicate test of early cupping than clinical observation. The possibility of reversing early cupping by therapy will be explored. The relationship between the quantitative measurement of optic nerve head cupping and visual field loss will be examined.